1. Technical Field
The present invention relates to mobile terminal such as an audio transmitting apparatus and a mobile communication terminal with a function to warn a user before occurring difficulties in transmission during transmitting voice and/or music data.
2. Description of Related Art
Audio signals are transmitted via short distance wireless links in either a bidirectional manner or a one directional manner between audio transmitting apparatuses such as a mobile communication terminal and a music player, and audio receiving apparatuses such as a hand-free telephone communication apparatus and a headset. In this case, audio data to be transmitted may include voice data, and/or music data. Also, as the communication method, for instance, a Bluetooth technique is employed.
This type of communication has vulnerability to deteriorations of communication qualities. That is, sound to be transmitted will be interrupted during transmission. For instance, a metal product is interposed between an audio 1, transmitting apparatus and an audio receiving apparatus, so that electromagnetic waves are shielded, or reflected by the metal product.
Accordingly, the below-mentioned operations are known. When a deterioration of a communication quality of a short distance wireless communication network is detected, since a compression ratio of the audio data be to transmitted is increased, a use efficiency of a buffer is increased so as to establish a margin capable of resending audio signals, so that sound interruptions hardly occur (refer to, for example, JP-A-2003-309541 (pages 2 to 3, FIG. 9).
When the above-described metal product corresponds to an article owned by a user of an apparatus and is moved based upon the will of the user, the user may furthermore move this metal product, so that the communication quality of the short distance wireless communication may be improved. On the other hand, a user may improve the communication quality of the short distance wireless communication network by moving either the audio transmitting apparatus and/or the audio receiving apparatus irrespective of such a fact as to whether or not the above-described metal product belongs to the article owned by the user, namely, whether or not the movement of the metal product is caused by the will of the user.
Also, in the case that an audio transmitting apparatus is arranged by a CPU and programs which are utilized by the CPU, such a possibility that the above-explained communication may be interrupted is not equal to zero, since a large number of these programs are executed in the audio transmitting apparatus, so that the CPU resources allocated to the short distance wireless communication process operation become insufficient.
The reason is given as follows: That is, since both audio transmitting apparatuses and audio receiving apparatuses are portable type apparatuses operated by electric power stored in batteries, it is important to reduce power consumption thereof. It is proper to design these audio transmitting apparatuses and audio receiving apparatuses in that CPUs which consume minimum necessary power are mounted thereon, namely CPUs having minimum required performance are mounted thereon.
When the CPU resources become insufficient, the user may operate to reduce loads given to the CPU, which are caused by either one program or plural programs under execution, so that the possibilities in which the communication is interrupted may be eliminated, or may be reduced.
However, in accordance with the method disclosed in JP-A-2003-309541, it is possible to delay that the communication is interrupted, but it is not always possible to avoid that the communication is interrupted. In the case that the communication quality of the short distance wireless communication network cannot be improved for a time duration longer than, or equal to a predetermined time duration, the above-explained method has the following problems. That is, a sound interruption happens to occur, so that unpleasant feelings are given to the user, or understandings of telephone communications are disturbed.